hearing aids circuit with 1.5 v supply

[silver101]

**broken link removed**


Please can you open the link above and explain me the detailed use and functionality of each components.
i also changed the supply to 3 v and output was better
also i changed the 10 k resistor to 4.7 k resistor and the output was better.

i will appreciate for a timely response. thankyou.

 

[audioguru]

The very simple circuit has only a few parts so why can't you see their functions?

If you learn about how resistors, capacitors and transistors work then you will see the function of each part just by looking at the schematic.

If you skipped many classes about electronics basics in school then we can't help you.

 

[silver101]

as a matter of fact i never missed classes. i am currently a 3.0 gpa holder.
i know the 1st transistor is used for biasing, and the 10k resistor is used for negative feedback.

i only merely asked because i wanted an enhancement of my knowledge, as my teacher would be taking a thorough demo of this project so thought i should revise in detail each step of the circuit.
i made this, and it works fine.
checked the output on a CRO as well, and even implemented it on the software Multisim.

 

[audioguru]

I haven't been to school for 45 years. My kids finished school many years ago. I never heard of 3.0 gpa in Canada.

The first transistor is part of the amplifier. It is biased by the 220k and 330k voltage divider resistors.
You are correct, the 10k resistor provides negative DC feedback. The 10uf capacitor prevents AC negative feedback.

 

[silver101]

thankyou.

what about the 2nd and the 3rd transistor. the signal is at low impedance when it reaches teh 2nd transistor right, the BC557

and oh, that;s probably because i am not from canada!

 

[audioguru]

what about the 2nd and the 3rd transistor?

All the transistors are common-emitter amplifiers.

the signal is at low impedance when it reaches teh 2nd transistor right, the BC557?

No.
The emitter of a transistor is a low impedance but impedances do not matter in this simple circuit.

i am not from canada!

Nobody knows where you are. From Mars?